Viruses are significant cause of cancer in normal humans and are an even more common cause of cancer in immune deficient humans such as organ transplant recipients or HIV infected people. Furthermore, analyses of the way viruses alter cell growth has frequently led to the delineation of novel pathways of cell growth control and oncogenicity. This Program enables the training of 2 to 3 pre- and 5 post-doctoral trainees each year in the laboratories of the 20 faculty members working in Viral Oncology at Harvard University. The research objectives of these laboratories include (1) mechanisms by which RNA tumor viruses get into cells (2) mechanisms by which small DNA tumor viruses including human papillomaviruses alter cell growth and cause cervical cancer (4) mechanisms by which viruses alter cell signal transduction, transcription, cell cycle regulation, and cell survival and the role of these processes in normal and tumor cell growth. Trainees are recruited by the Virology and Biological and Biomedical Science Programs and enter the program because of their interest in viral oncology. Pre-doctoral students pursue 3 semesters of course work in molecular biology, genetics, cell biology, virology, and immunology while engaged in laboratory research training in viral oncology. Thereafter, they are fully engaged in mentored thesis research. Post-doctoral fellows engage full time in mentored research training research training. Pre- and post-doctoral students also participate in seminars, journal clubs, and research conferences including viral oncology and oncology research conferences. Trainees are jointly mentored by their principal research trainer and by other program faculty. On completion of their thesis research pre-doctoral students will be prepared for post-doctoral training and post-doctoral students will be prepared for independent research in viral oncology and related disciplines.